Drive system and image forming apparatus including same

ABSTRACT

A drive system includes multiple vibrating members that tend to vibrate when these members are driven and a holding system to hold the multiple vibrating members. The holding system at least includes a first holding unit and a second holding unit superimposed on and partially connected to each other. The multiple vibrating members include a first vibrating member and a second vibrating member. The first vibrating member is held by the first holding unit and is not held by the second holding unit. The second vibrating member is held by the second holding unit and is not held by the first holding unit. At least one of the first vibrating member and the second vibrating member is a driving device to drive another member as a drive source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35U.S.C. §119(a) to Japanese Patent Application Nos. 2013-181971, filed onSep. 3, 2013, 2013-187129, filed on Sep. 10, 2013, and 2014-048946,filed on Mar. 12, 2014 in the Japan Patent Office, the entiredisclosures of which are hereby incorporated by reference herein.

BACKGROUND

1. Technical Field

This invention relates to a drive system and an image forming apparatus,such as a copier, a printer, a facsimile machine, or a multifunctionalmachine having multiple functions of these devices, etc., including thedrive system.

2. Related Art

In an image forming apparatus, many drive systems (i.e., drive sources)are generally employed to execute an image forming operation. Forexample, these drive systems are used to drive a photosensitive body, atransfer belt, or the like, for example. These drive systems usuallygenerate a noise during an image forming process, thereby raising aproblem. That is, since many components are mechanically connected toeach other, noise may occur due to vibration of these components or thelike when drive force is transmitted to these components from the drivesystem.

Many attempts have been made to eliminate or reduce such noise. Forexample, as shown in FIG. 4, a motor 200 acting as a drive systemprovided in an image reading unit is fixed to a supporting plate 201with a pair of motor fixing screws 202 to suppress vibration of a driveunit employed in an image forming apparatus. The supporting plate 201 isfixed to a housing, not shown, at three places via multiple vibrationabsorbers 203 using multiple supporting plate fixing screws 204,respectively, for example.

On a rear side of the supporting plate 201, opposite a front side onwhich the motor 200 is held, a drive force output gear, not shown, and adriving pulley 206 are placed. Drive force from the motor 200 isaccordingly transmitted via the drive force output gear from the motor200 to the driving pulley 206. The driving pulley 206 then transmits thedrive force to a belt 207 wound therearound. In the conventional imagereading unit, a tilting angle adjusting screw 210 is also disposed onthe supporting plate 201 as well to adjust an inclination of thesupporting plate 201 by changing a fastening degree thereof not toexcessively tilt toward the housing. With this arrangement,amplification of the vibration of the supporting plate 201, generallycaused when the position of the driving pulley 206 deviates and meshingwith the belt 207 deteriorates, is inhibited.

In another conventional attempt, various vibrations occurring in animage forming apparatus are separated into those that generatelow-frequency noise and those that generate the high-frequency noisegenerally deemed unpleasant, respectively. Then, the high-frequencysound is rendered inaudible by enlarging the low-frequency sound at thesame time as a countermeasure to reduce the sound, movement of a motoris smoothed by reducing a stepping angle of the motor or sound occurringinside walls is absorbed by placing sound absorbing material thereon,for example.

These countermeasures taken to either absorb the above-describedvibrations and/or the sound or obscure the high-frequency sounds or thelike have been successful to a certain extent in suppressing noise inthe conventional image forming apparatus. However, since there existvarious types of image forming apparatuses each having multiple drivesystems for driving various mechanisms, respectively, installed therein,the above-described countermeasures are not always completely effectivefor it is generally preferable to prepare various countermeasuresagainst noise employable in a greater number of types of image formingapparatuses.

SUMMARY

Accordingly, one aspect of the present invention provides a novel drivesystem that includes: at least one vibrating member to generatevibration when it is driven; and a holding system to hold the at leastone vibrating member. The holding system at least includes a firstholding unit and a second holding unit superimposed on and partiallyconnected to each other.

Another aspect of the present invention provides a novel image formingapparatus with a drive system that includes at least one vibratingmember to generate vibration when it is driven and a holding system tohold the at least one vibrating member. The holding system at leastincludes a first holding unit and a second holding unit superimposed onand partially connected to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of theattendant advantages thereof will be more readily obtained assubstantially the same becomes better understood by reference to thefollowing detailed description when considered in connection with theaccompanying drawings, wherein:

FIG. 1 is a diagram schematically illustrating an exemplaryconfiguration of an image forming apparatus according to one embodimentof the present invention, to which various drive systems according toseveral practical examples are applied;

FIG. 2A is a cross-sectional view schematically illustrating a drivesystem according to a first embodiment of the present invention;

FIG. 2B is a cross-sectional view schematically illustrating a motor anda motor gear included in the drive system according to the firstembodiment of the present invention;

FIG. 3 is a cross-sectional view schematically illustrating a drivesystem according to a second embodiment of the present invention;

FIG. 4 is a diagram schematically illustrating a configuration of animage reading unit having a drive system employed in a conventionalimage forming apparatus;

FIG. 5A is a cross-sectional view schematically illustrating a drivesystem according to a third embodiment of the present invention;

FIG. 5B is a front view schematically illustrating a configuration ofthe drive system of the third embodiment of the present invention; and

FIG. 6 is a cross-sectional view schematically illustrating a drivesystem according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views thereofand in particular to FIG. 1, an exemplary image forming apparatus 1 isconfigured by the below described various devices. That is, the imageforming apparatus 1 may include an exposing unit 2, an image formingunit 3, a transferring unit 4, a sheet feeding unit 5, a sheet conveyingpath 6, a fixing unit 7, and a sheet ejecting unit 8 or the like asshown there.

The exposing unit 2 is located at an upper section in the image formingapparatus 1 and includes a light source that emits a laser light beam orthe like and various optical systems or the like. Specifically, theexposing unit 2 irradiates a laser light beam generated based on imagedata obtained from an image acquiring device, not shown, per colorseparation component toward a photoconductor employed in an imageforming unit 3 described later in detail and exposes a surface of thephotoconductor.

The image forming unit 3 is located below the exposing unit 2 and hasmultiple processing units 31 detachably attached to the image formingapparatus 1. Each of the multiple processing units 31 is composed of aphotoconductive drum 32 capable of bearing a toner image thereon, anelectric charging roller 33 that uniformly charges a surface of thephotoconductive drum 32, a developing unit 34 to supply toner onto asurface of the photoconductive drum 32, and a photoconductor cleaningblade 35 to clean the surface of the photoconductive drum 32, etc. Here,the multiple processing units 31 have four processing units 31 (i.e.,31Y, 31C, 31M, and 31Bk) corresponding to different component colors ofyellow, cyan, magenta, and black (i.e., color separation components) ofa color image. However, since these four processing units 31 (i.e., 31Y,31C, 31M, and 31Bk) have substantially the similar configurations witheach other except for accommodation of different color toner particles,respective reference alphabets are omitted herein after.

A transferring unit 4 is located beneath the image forming unit 3. Thetransferring unit 4 is composed of an endless intermediate transfer belt43 stretched and suspended by a driving roller 41 and a driven roller 42to be able to run therearound, a cleaning blade unit 44 for cleaning asurface of the intermediate transfer belt 43, and multiple primarytransfer rollers 45 opposed to the photoconductive drums 32 of therespective processing units 31 across the intermediate transfer belt 43or the like. The respective primary transferring rollers 45 pressagainst an inner circumferential surface of intermediate transfer belt43 at prescribed locations to form primary transferring nips betweensections where the intermediate transfer belt 43 is thereby pressed andsections where the photoconductive drums 32 contact thereto,respectively.

A secondary transfer roller 46 is also disposed being opposed to thedriving roller 41 wound by the intermediate transfer belt 43 across theintermediate transfer belt 43. The secondary transfer roller 46 ispressed against an outer circumferential surface of the intermediatetransfer belt 43 to form a secondary transfer nip thereon at a positionat which the secondary transfer roller 46 and the intermediate transferbelt 43 contact each other. A waste toner box 47 is also disposed belowthe intermediate transfer belt 43 to accommodate waste toner particlescollected by the cleaning blade unit 44 from the intermediate transferbelt 43 via a waste toner transfer hose, not shown, when theintermediate transfer belt 43 is thereby cleaned.

The sheet feeding unit 5 is located at a lower section in the imageforming apparatus 1 and includes a sheet feeding cassette 51accommodating multiple recording sheets P and a sheet feeding roller 52for carrying out the recording sheet P from the sheet feeding cassette51 or the like.

A sheet conveying path 6 defining a sheet conveyance route is providedto convey the recording sheet P carried out from the sheet feeding unit5. The sheet conveying path 6 includes a pair of registration rollers 61and multiple pairs of conveyor rollers, not shown, optionally positionedupstream of the sheet ejecting unit 8 as described later more in detail.

A fixing unit 7 has a fixing roller 72 heated by a heating source 71 anda pressing roller 73 capable of pressing itself against the fixingroller 72 or the like.

The sheet ejecting unit 8 is provided most downstream of the sheetconveying path 6 in the image forming apparatus 1. In the sheet ejectingunit 8, there are provided a pair of sheet ejecting rollers 81 to drainthe recording sheet P outside the image forming apparatus 1 and a sheetexiting tray 82 to stack the recording media drained by the pair ofsheet ejecting rollers 81 thereon.

Now, an essential operation of the image forming apparatus 1 is d hereinbelow describe in detail with reference to FIG. 1.

When image forming operation starts in the image forming apparatus 1,different multiple electrostatic latent images are formed on surfaces ofthe photoconductive drums 32 of the processing units 31Y, 32C, 31M, and31BK, respectively. Image information to expose the surfaces of therespective photoconductive drums 32 are monochrome color imageinformation obtained by dissolving a prescribed full-color image intorespective image information of yellow, cyan, magenta, and black colors.Hence, when toner particles are supplied to those from the developingunits 34, the respective electrostatic latent images formed on thephotoconductive drums 32 are visualized to be corresponding toner images(i.e., developed images).

Subsequently, the intermediate transfer belt 43 is driven to run in adirection as shown by arrow A in the drawing as the driving roller 41provided in the transferring unit 4 is driven and rotatedcounterclockwise in the drawing. To each of the primary transferringrollers 45, a voltage subjected to either constant voltage control orconstant current control having a reverse polarity to a polarity ofcharged toner is applied. With this, an electric transferring field isformed in each of the primary transferring nips formed between therespective primary transferring rollers 45 and the photoconductive drum32. Accordingly, color toner images formed on the respectivephotoconductive drums 32 of the processing units 31Y, 31M, 31C, and 31Bkare successively transferred and superimposed at a prescribed positionon the intermediate transfer belt 43 by the electric transferring fieldsformed in the above-described primary transferring nips, respectively.Hence, a full-color toner image is formed on the surface of theintermediate transfer belt 43 in this way.

Whereas, when the image forming operation is initiated and accordinglythe sheet feeding roller 52 of the sheet feeding unit 5 disposed in thelower section of the image forming apparatus 1 is driven and is rotated,the recording sheet P housed in the sheet feeding cassette 51 is sentout (i.e., launched) into the sheet conveying path 6. The recordingsheet P sent out into the sheet conveying path 6 is timed by the pair ofregistration rollers 61, and is further sent to the secondarytransferring nip formed between the secondary transfer roller 46 and thedriving roller 41 opposed thereto. To the secondary transfer roller 46,a transfer voltage having a reverse polarity to a polarity of chargedtoner of a toner image borne on the intermediate transfer belt 43 isapplied to form another electric transferring field in the secondarytransfer nip. Accordingly, the toner image on the intermediate transferbelt 43 is transferred onto a recording sheet P in a block at once inthe other electric transferring field formed in the secondary transfernip.

The recording sheet P onto which the toner image is transferred issubsequently conveyed to the fixing unit 7. The recording sheet P isthen heated by the fixing roller 72 heated by the heating source 71 andis pressed by a pressing roller 73, so that the toner image is fixedonto the recording sheet P. The recording sheet P with the fixed tonerimage thereon is subsequently separated from the fixing roller 72, andis further conveyed downstream thereof by a pair of conveyor rollers,not shown. The recording sheet P is subsequently ejected by the pair ofsheet ejecting rollers 81 onto the sheet exiting tray 82 in the sheetejecting unit 8. Here, residual toner adhering to the intermediatetransfer belt 43 after the transfer process is subsequently removedtherefrom by the cleaning blade unit 44 or the like. The removed toneris subsequently conveyed toward a waste toner box 47 by a screw or awaste toner transfer hose and the like, not shown, and is ultimatelycollected in the waste toner box 47.

Although the above-described image formation is executed to form thefull-color image on the recording sheet P, the present invention is notlimited thereto, and a monochromatic image can be formed by optionallyusing any one of the four processing units 31Y, 31C, 31M, and 31Bk.Otherwise, dual or trivalent color images can be formed by using two orthree processing units out of the four processing units 31Y, 31C, 31M,and 31Bk as well.

Now, an exemplary drive unit according to one embodiment of the presentinvention is described with reference to FIGS. 2A and 2B and applicabledrawings. In an image forming apparatus 1, multiple drive units aregenerally used in various image forming processes to drive and operateprescribed structures (i.e., systems) including a photoconductive drum32, a driving roller 41 for driving an intermediate transfer belt 43, asheet feeding mechanism, an image reading system, and a sheet ejectingsystem or the like.

FIG. 2A is a cross-sectional view schematically illustrating a drivesystem according to a first embodiment of the present invention. Asshown there, a motor 100 acting as a drive system (i.e., a firstvibrating member) is held by a first plate 101 a acting as a firstholding unit. The motor 100 is connected to a driving target 105 througha motor gear 102, a gear 103, and a second driving shaft 104 acting as asecond vibrating member. On an opposite side to the side in which themotor 100 is held (i.e., a side in which the driving target 105 islocated), a second plate 107 a and a second bracket 107 b other than thefirst plate 101 a and a first bracket 101 b are provided. The firstbracket 101 b is connected to the second bracket 107 b by a pair ofstuds 106.

The driving shaft 104 is held by the first bracket 101 b acting as asecond holding unit and the second bracket 107 b as well. The drivingshaft 104 accordingly functions to transmit drive force to the drivingtarget 105 upon receiving it from the motor 100 through the motor gear102 and the gear 103. The first plate 101 a and the first bracket 101 b,and the second plate 107 a and the second bracket 107 b are respectivelysuperimposed on and partially coupled to each other via a structuraldevice such as a nail, etc., or a fastener, such as a screw, etc. Hence,the plate 101 a and the bracket 101 b function as holding sections whichhold the motor 100 and the driving shaft 104, respectively.

FIG. 2B is a cross-sectional view schematically illustrating the motor100 and the motor gear 102 taken when the first plate 101 a holds themotor 100. As shown there, in the first bracket 101 b, a first hole Q1is formed at a section at which the motor gear 102 penetrates, so thatthe first bracket 101 b contacts neither the motor 100 nor the motorgear 102. Because of this, the motor 100 is held by the first plate 101a, but is not held by the first bracket 101 b. Similarly, as shown inFIG. 2A, since a second hole Q2 is also formed in the first plate 101 a,the driving shaft 104 is held by the first bracket 101 b, but is notdirectly held by the first plate 101 a.

Thus, although vibration caused by the motor 100 when it operates istransmitted to the first plate 101 a that holds the motor 100, it is notdirectly transferred to the first bracket 101 b which does not contactthe motor 100, accordingly. On the other hand, since the vibrationcaused by the motor 100 reaches the driving shaft 104 via the motor gear102 and the gear 103 when the motor 100 operates and rotates the drivingtarget 105 via the driving shaft 104. Hence, although vibration causedby rotation of the driving shaft 104 is transmitted to the first bracket101 b that holds the driving shaft 104, it is not transmitted directlyto the first plate 101 a that does not contact the driving shaft 104.With such a configuration, the first plate 101 a directly receivestransmission of the vibration from the motor 100, and the first bracket101 b also directly receives transmission of the vibration from thedriving shaft 104, respectively. Specifically, the different membersdirectly transmit the vibrations to the first plate 101 a and the firstbracket 101 b, respectively. Since the first plate 101 a and the firstbracket 101 b are only partially coupled together, these members do notsynchronously vibrate in a body with each other even receiving thetransmission of the vibration, phases of the vibrations of these membersmay be shifted from each other. Because of this, since these vibrationsof the first plate 101 a and the first bracket 101 b interfere with eachother, the vibrations of these members can be reduced. At the same time,vibrations to travel from these members to surroundings are also reducedsimilarly as well. Hence, since the first plate 101 a and the firstbracket 101 b are superimposed on and partially being combined, thevibrations traveling from the motor 100 and the driving shaft 104 can bereduced. Thus, suppression of the vibration and reduction of the noisecan be obtained at the same time in the holding sections, its peripheralmechanisms (i.e., the surroundings), and the entire drive system aswell.

The second plate 107 a also has a third hole Q3 therein and isaccordingly configured not to contact the driving shaft 104. That is,the driving shaft 104 is held by the second bracket 107 b at its oneside end closer to the driving target 105. The second bracket 107 b alsoholds the pair of studs 106 at the same side as holding the drivingshaft 104 as well.

The pair of studs 106 is also held by the first bracket 101 b at itsopposite side ends to those held by the bracket 107 b. As describedabove, because the vibration of the driving shaft 104 is communicated toit, the first bracket 101 b also vibrates and transmits the vibration tothe second bracket 107 b through the pair of studs 106 as well.

Since the vibrations are communicated from the pair of studs 106 and thedriving shaft 104 to it, the second bracket 107 b accordingly vibratesas well. However, since it contacts neither the pair of studs 106 northe driving shaft 104, the second plate 107 a does not receivetransmission of the vibration from them. However, the vibration istransmitted to the second plate 107 a from the second bracket 107 bsuperimposed thereon.

At this moment, since the second plate 107 a and the second bracket 107b are superimposed on each other while only partially connected to eachother as is similar to the relation between the first plate 101 a andthe first bracket 101 b, the second plate 107 a and the second bracket107 b do not synchronously vibrate in a body again and accordinglyphases of vibrations of these members may be shifted from each othereven receiving transmissions of vibrations, respectively. Hence, sincethe vibrations of these members interfere with each other, thesevibrations are reduced with vibration absorbing effect. Accordingly, atthis moment, the second plate 107 a and the second bracket 107 b act asfirst and second holding units, respectively, and receive the vibrationsfrom two different vibrating members (i.e., the pair of studs 106 andthe driving shaft 104).

Thus, when a difference in magnitude of vibration between two differentmembers (e.g., a plate and a bracket) superimposed on each other isrelatively small, the vibration can be cancelled or sufficiently reducedby superimposing these two members on each other. By contrast, however,when the difference in magnitude of vibration between two differentmembers (e.g., a plate and a bracket) superimposed on each other isrelatively large, since the larger vibration cannot be sufficientlycancelled or reduced, damper effect cannot be always sufficientlyobtained. Therefore, it is desirable that the difference in magnitude ofvibration between two different members is adjusted to decrease.

Here, because it can generally reduce vibration of a member if arigidity of the member is enhanced, it is possible to adjust adifference in magnitude of vibration between two different members byenhancing the rigidity of one of the members that generates largervibration than the other member.

When magnitudes of vibrations of the plate 101 a or 107 a and thebracket 101 b or 107 b of one embodiment of the present invention iscompared with each other, the magnitude of the vibration of the bracket101 b or 107 b is larger than that of the plate 101 a or 107 a, becausethe bracket 101 b or 107 b directly receives transmission of drive forcevia a meshing section of the bracket 101 b or 107 b which meshes withthe driving shaft 104 and, by contrast, the plate 101 a or 107 areceives transmission of the vibration via a third member contactingthereto.

As described heretofore, according to one embodiment of the presentinvention, to the bracket 101 b or 107 b, only the driving shaft 104 isconnected via the single gear 103. However, multiple gears are alsocommonly employed to connect to the bracket 101 b or 107 b, and amagnitude of vibration transmitted to the bracket 101 b or 107 b mayincrease in such a situation.

In view of the above-described context, it is recognized that amagnitude of each of vibrations transmitted to the first bracket 101 band the second bracket 107 b each connected to the driving shaft 104 viathe gear 103 tend to more easily grow than that transmitted to each ofthe plates 101 a or 107 a.

Because of this, in the drive system according to one embodiment of thepresent invention, rigidity of each of the brackets 101 b and 107 b isset higher than that of each of the plates 101 a and 107 a. With this,by reducing the difference in vibration between the bracket 101 b or 107b and the plate 101 a or 107 a, vibration absorbing effect can be moreeffectively obtained.

Hence, in one embodiment of the present invention, a thickness of eachof the brackets 101 b and 107 b is made thicker than each of the plates101 a and 107 a, for example, to enhance the rigidity thereof. However,a method of enhancing the rigidity is not limited to the above-describedexample, and respective materials making these members 101 b, 107 b, 101a, and 107 a can be changed to control the rigidity of each of themembers 101 b, 107 b, 101 a, and 107 a, alternatively.

Hence, as described as a first situation in the first embodiment, thefirst and second holding units (i.e., the first plate 101 a and thefirst bracket 101 b) hold different vibrating members (i.e., the motor100 and the driving shaft 104) and receive vibrations from thesedifferent vibrating members, respectively. As a second situation in thefirst embodiment, the multiple vibrating members (i.e., the pair ofstuds 106 and the driving shaft 104) are commonly held only by aprescribed holding unit (i.e., the second bracket 107 b) therebytransmitting the vibrations only thereto so that another prescribedholding unit (i.e., the second plate 107 a) does not directly receivethe vibrations from these multiple vibrating members (i.e., the pair ofstuds 106 and the driving shaft 104).

In the former (i.e., first) situation, since the vibrations transmittedto the respective holding units from the vibrating members havedifferent phases (i.e., shifted phases) from each the other andaccordingly mutually interfere with each other, thereby reducing theseown magnitudes while obtaining a vibration absorbing effect. Bycontrast, in the latter (i.e., second) situation, since the vibrationsare transmitted initially to the prescribed first holding unit from thevibrating members and are secondary transmitted to the second holdingunit via the prescribed first holding unit, the second holding unitsecondarily vibrates. Accordingly, at that moment, since the vibrationsof the first and second holding units have the different phases fromeach other and accordingly interfere with each other, magnitudes of thevibrations can be reduced with a vibration absorbing effect.

When both of the first and second situations are compared with eachother, because the vibration of the second holding unit of the lattersituation is a secondarily generated, the magnitude of the vibration issmaller and accordingly a degree of reduction of each of the vibrationscaused by the interference of vibrations may be smaller. Accordingly,since the former first situation allows the greater reduction ofvibration by the interference of vibrations, and the holding units andthe peripheral mechanisms as well as the drive system as a whole canobtain the greater vibration reduction effects.

Hence, according to one embodiment the present invention, as onesituation (i.e., a vibration traveling system), the motor 100 acts as adrive system to generate drive force and cause vibration by itself anddirectly communicates these drive force and vibration to the holdingunit. In another situation according to one embodiment the presentinvention, a prescribed member, such as the driving shaft 104, etc.,communicates the vibration caused by the drive force of the drive systemto the holding unit upon receiving transmission of the vibration eitherdirectly or indirectly. Accordingly, in this point of view, anothersituation other than the situations as descried in the first embodimentcan be considered, in which the first and second holding units directlyreceive transmissions of vibrations from different drive systems,respectively. Yet another situation can be also considered as well, inwhich the first and second holding units receive transmission ofvibrations from vibrating members which receive the vibrations eitherdirectly or indirectly from different drive systems, respectively.

Now, a drive system according to a second embodiment of the presentinvention is described with reference to FIG. 3 that schematicallyillustrates a cross-sectional view thereof. In the drive system of thesecond embodiment, the motor 100, the first plate 101 a, and the firstbracket 101 b are fastened by a pair of screws 110. The motor 100 isheld by both of the first plate 101 a and the first bracket 101 b.Similar to the drive system of the first embodiment, the motor 100 isconnected to the driving target 105 through the motor gear 102, the gear103, and the driving shaft 104 as well. The driving shaft 104 is held bythe first bracket 101 b as shown there. However, the driving target 105is omitted here from the drawing.

Since the motor 100 is held by both of the first plate 101 a and thefirst bracket 101 b, vibration caused by the motor 100 is communicatedto both the first plate 101 a and the first bracket 101 b. Also,vibration cause by the driving shaft 104 is transmitted to the firstbracket 101 b as well. Accordingly, at this moment, as in the drivesystem of the first embodiment, since the first plate 101 a and thefirst bracket 101 b are only partially coupled with and superimposed oneach other, phases of the vibrations of both of the first plate 101 aand the first bracket 101 b deviate (i.e., shift) from each other, andaccordingly the vibrations of the both of the first plate 101 a and thefirst bracket 101 b interference with each other thereby reducing thevibrations with a vibration absorbing effect. However, in the drivesystem of the second embodiment, the number of vibration transferringdestinations is greater than that in the drive system of the firstembodiment, because the motor 100 transmits its own vibration to both ofthe first plate 101 a and the first bracket 101 b. As a result, thetotal magnitude of the vibrations in the system as a whole may begreater than that in the drive system of the first embodiment.

Hence, according to the second embodiment, the first vibrating member(i.e., the motor 100) is held by both the first and second holding units(i.e., the first plate 101 a and the first bracket 101 b), while thesecond vibrating member (i.e., the driving shaft 104) is held only byone of the holding units (e.g., the first bracket 101 b). In the secondembodiment, however, the second vibrating member (i.e., the drivingshaft 104) can be held by both the first and second holding units (i.e.,the first plate 101 a and the first bracket 101 b).

Further, as shown there, the motor 100 of the second embodiment ispositioned using a spigot joint 108 attached to the motor 100 and isscrewed with a pair of screws 110 on the first plate 101 a or the like.Then, the motor 100 as a unit is enabled to manually rotate around amotor axis as a rotational center thereof to change its fixed angularposition regarding the first plate 101 a in this second embodiment.Hence, by changing it and thereby adjusting the fixed angular positionof the motor 100 in this way, the vibration can be mostly minimized.

Here, in the second embodiment, since securing of the motor 100 to thefirst plate 101 a and partial securing of the first plate 101 a to thefirst bracket 101 b are made by the common screw 110 as shown, thenumber of components to be used to assemble the drive unit can bereduced.

Here to fore, the typical configurations of the drive system aredescribed based on the first and second embodiments of the presentinvention. However, since multiple drive units are generally used insideof the image forming apparatus, and sizes of the motor 100 acting as thedrive system and the driving target 105 vary depending on a function ofthe drive system or the like, it is important to appropriately selectthe first plate 101 a and the first bracket 101 b suitable to therespective drive system to obtain a greater vibration absorbing effect.In this context, an adjusting device that adjusts the vibrationabsorbing effect is herein below described more in detail with referenceto applicable drawings.

The method of adjusting the vibration absorbing effect by changing theangular mounting position of the motor 100 is described earlier.However, the method of adjusting the vibration absorbing effect is notlimited to that of changing the angular mounting position of the motor100, but includes that of changing the connecting position of the firstplate 101 a acting as the holding unit to the first bracket 101 b aswell. For example, when both of the first plate 101 a and the firstbracket 101 b are partially coupled with each other using the fasteningscrew, multiple screw holes are formed on each of the first plate 101 aand the first bracket 101 b at multiple locations thereon, respectively,to be optionally used to screw the first plate 101 a on the firstbracket 101 b.

Further, in the drive systems of the above-described embodiments, onlytwo sheet-like members, such as the first plate 101 a, the first bracket101 b, etc., are superimposed on each other as the holding units.However, the number of sheet-like members to be superimposed on eachother to constitute the holding units is not limited only to the twosheet-like members, and three, four, and more number of sheets can bealso superimposed on each other by enhancing the number of sheet-likemembers as well. Furthermore, a thickness of each of the holding unitsto be superimposed is not necessarily the same as others, and only aspecific holding unit can be either thicker or thinner than the otherholding unit as well. That is, by differentiating the thickness of thefirst plate 101 a from that of the first bracket 101 b, for example, byeither thinning or thickening the first plate 101 a than the firstbracket 101 b and accordingly appropriately adjusting the thickness ofthe first plate 101 a and the first bracket 101 b, an optimal vibrationabsorbing effect with effective vibration reduction can be obtained atthe same time as well.

Further, each of the holding units can be made of different materialfrom others to obtain the optimal vibration absorbing effect witheffective vibration reduction as well. That is, the first plate 101 amay be made of material either to more easily communicate vibration thanthat of the first bracket 101 b or to more hardly transmit the same thanthat of the first bracket 101 b in order to obtain the optimal vibrationabsorbing effect with the effective vibration reduction.

Now, a drive system according to a third embodiment of the presentinvention is described with reference to FIGS. 5A and 5B, wherein FIG.5A is a cross-sectional view schematically illustrating the drive systemof the third embodiment of the present invention, and FIG. 5B is a frontside view schematically illustrating a configuration of the drive systemof the third embodiment of the present invention.

In the drive system of the third embodiment of the present invention,each of pair of motors 100 is held by a first plate 120 a serving as afirst holding unit, and is connected to the motor gear 102, a first gear121, and a second gear 122 as well. The first plate 120 a is positionedat a prescribed portion of a side plate 123. Drive force of the motor100 is accordingly transmitted to each of units of a photoconductor andan intermediate transfer belt or the like via the motor gear 102, thefirst gear 121, and the second gear 122.

Also, onto the first plate 120 a, a second plate 120 b as a secondholding unit is superimposed and is partially connected thereto withmultiple screws, not shown. Hence, since the second plate 120 b issuperimposed on the first plate 120 a, a total thickness of the firstand second plates 120 a and 120 b increases more than that of one plate120 a or 120 b, thereby enhancing the thickness and accordingly therigidity thereof.

Hence, the vibration of the first plate 120 a caused when the motor 100transmits its drive force thereto can be minimized. The vibrations canbe further reduced due to interfere of vibrations of these two first andsecond plates 120 a and 120 b as already discussed in the firstembodiment of the present invention.

Furthermore, by adjusting the thickness of the second plate 120 b inaccordance with a magnitude of the vibration transmitted thereto, anoptimal vibration absorbing effect with vibration reduction can beobtained.

Here, as shown in FIG. 5B, a pair of openings 130 is formed at sectionsin the second plate 120 b, at which the pair of motors 100 is deployed,not to contact and avoid the pair of motors 100, respectively. If theopening 130 does not exist, since the motor 100 is necessarily placed onthe second plate 120 b, a width of the drive unit grows by an amount ofthe thickness of the second plate 120 b as a result. Hence, due toprovision of the opening 130, the second plate 120 b can avoidcontacting the motor 100 and a prescribed member that contacts the firstplate 120 a as well, thereby enabling the drive unit to maintained thewidth thereof (i.e., not to grow). For this reason, even when thethickness of the second plate 120 b is adjusted to increase to be theoptimal value for the purpose as described earlier, the total width ofthe drive unit does not change except for a situation in which thesecond plate 120 b becomes thicker than the motor 100 in the thirdembodiment of the present invention.

In the driving device of the third embodiment, although the pair ofmotors 100 is typically disposed, only one or three or more motors 100can be employed as well.

Now, a drive system according to a fourth embodiment of the presentinvention is described with reference to FIG. 6 that schematicallyillustrates a cross-sectional view of the drive system. The firstbracket 101 b and the second bracket 107 b of the fourth embodiment havetwo pair of flanges 140 and 150 as reinforcing sections at their sideends, respectively. That is, by providing these two pair of flanges tothe respective first and second brackets 101 b and 107 b brackets andthereby enhancing their strengths (i.e., rigidities), vibrations to becaused at these sections can be likely reduced.

Here, in the drive system of the fourth embodiment, the first plate 101a and the second plate 107 a are shorter than the first bracket 101 band the second bracket 107 b, respectively. Consequently, the two pairof flanges 140 and 150 of the first and the second brackets 101 b and107 b do not overlap with the respective first and the second plates 101a and 107 a.

Hence, as described previously, these two pair of flanges 140 and 150are more rigid than the rest of these in the respective first and secondbrackets 101 b and 107 b, vibrations to be caused by these two pair offlanges 140 and 150 can be more effectively suppressed. As a result, atthese two pair of flanges 140 and 150, a vibration absorbing effectobtained by superimposing the first and second plates 101 a and 107 a oneach other is not necessarily required. Since the first and secondplates 101 a and 107 a are not overlapped with the respective these twopair of flanges 140 and 150, the first plate 101 a and the second plate107 a can be shortened, thereby reducing cost and weight of the drivesystem.

Hence, in the fourth embodiment, as the reinforcing sections of theholding units, although the flanges are provided to the respectivebrackets at their side ends, only a thickness of each of these side endsmay be thickened to enhance the strength (i.e., rigidity) as well.Further, if vibration transmitted to each of the first and second plates101 a and 107 a is larger than that transmitted to each of the first andsecond brackets, the reinforcing section can be established in each offirst and second plates 101 a and 107 a, for example.

Further, the image forming apparatus employed in the various embodimentsof the present invention is not limited to the color image formingapparatus as shown in FIG. 1, and can be a monochrome image formingapparatus, such as a copier, a printer, a facsimile machine, etc., and acomplex machine prepared by combining multiple functions of thesedevices.

Accordingly, according to one aspect of the present invention, becausethe first and second holding units are only partially connected to eachother, although vibrations transmitted from vibrating members aretransmitted to first and second holding units, the first and secondholding units do not vibrate synchronizingly, and accordingly phases ofthe vibrations of these first and second holding units are shifted fromeach other, the vibrations of those first and second holding unitsinterfere with each other thereby reducing magnitudes of thesevibrations. Consequently, the vibrations transmitted to and travelingfrom the holding units can be absorbed and reduced at the same timewhile also reducing a noise in the entire drive system. That is, a drivesystem includes at least one vibrating member to generate vibration whenit is driven, and a holding system to hold the at least one vibratingmember. The holding system at least includes a first holding unit and asecond holding unit superimposed on and partially connected to eachother.

According to another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be effectivelyabsorbed and reduced at the same time while also reducing a noise in theentire drive system. That is, the at least one vibrating member is atleast composed of a first vibrating member and a second vibratingmember.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, the first vibrating member isheld by the first holding unit and is not held by the second holdingunit, and the second vibrating member is held by the second holding unitand is not held by the first holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, the first vibrating member isheld by both of the first holding unit and the second holding unit, andthe second vibrating member is held by at least one of the first holdingunit and the second holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, both of the first vibratingmember and the second vibrating member are held by one of the firstholding unit and the second holding unit, and both of the firstvibrating member and the second vibrating member are not held by theother one of the first holding unit and the second holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, any one or both of the firstvibrating member and the second vibrating member is a driving device ordriving devices to drive by itself or themselves as a drive source ordrive sources.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, a thickness of each of thefirst holding unit and the second holding unit in an overlappingdirection in which the first holding unit and the second holding unitare superimposed, is enabled to vary in accordance with a magnitude ofvibration transmitted to each of the first holding unit and the secondholding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, the first holding unit andthe second holding unit are made of different material from each other.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, a connecting position, atwhich the first holding unit and the second holding unit connect to eachother, is enabled to vary in accordance with a magnitude of vibrationtransmitted to the first holding unit and the second holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, the second holding unit isshaped not to contact any one of the first and second vibrating memberscontacting the first holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, a thickness of the secondholding unit in an overlapping direction, in which the first holdingunit and the second holding unit are superimposed, is enabled to vary inaccordance with a magnitude of vibration transmitted to the secondholding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, a strengths or a rigidity ofone of the first holding unit and the second holding unit receivingtransmission of a greater magnitude of the vibration than that of theother one of the first holding unit and the second holding unit is sethigher than that of the other one of the first holding unit and thesecond holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, the rigidity of one of thefirst holding unit and the second holding unit is enhanced by thickeningthe one of the first holding unit and the second holding unit thatreceives transmission of a greater magnitude of the vibration than theother one of the first holding unit and the second holding unit.

According to yet another aspect of the present invention, the vibrationstransmitted to and traveling from the holding units can be moreeffectively absorbed and reduced at the same time while also reducing anoise in the entire drive system. That is, one of the first holding unitand the second holding unit includes a reinforced portion at itsprescribed position, the reinforced portion having a greater rigiditythan the rest of the reinforced portion in one of the first holding unitand the second holding unit. The reinforced portion excludes a portionin which the first holding unit and the second holding unit aresuperimposed on and partially connected to each other.

Numerous additional modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, thepresent invention may be executed otherwise than as specificallydescribed herein. For example, the drive system and the image formingapparatus with the same are not limited to the above-described variousembodiments and may be altered as appropriate.

What is claimed is:
 1. A drive system comprising: at least one vibratingmember to generate vibration when it is driven; and a holding system tohold the at least one vibrating member, wherein the holding system atleast includes a first holding unit and a second holding unit, the firstholding unit and the second holding unit superimposed on and partiallyconnected to each other, and a thickness of each of the first holdingunit and the second holding unit in a direction in which the firstholding unit and the second holding unit are superimposed is variable inaccordance with a magnitude of vibration transmitted to each of thefirst holding unit and the second holding unit.
 2. The drive system asclaimed in claim 1, wherein the at least one vibrating member comprisesa first vibrating member and a second vibrating member.
 3. The drivesystem as claimed in claim 2, wherein the first vibrating member is heldby the first holding unit and is not held by the second holding unit,and the second vibrating member is held by the second holding unit andis not held by the first holding unit.
 4. The drive system as claimed inclaim 2, wherein the first vibrating member is held by both of the firstholding unit and the second holding unit, wherein the second vibratingmember is held by at least one of the first holding unit and the secondholding unit.
 5. The drive system as claimed in claim 2, wherein both ofthe first vibrating member and the second vibrating member are held byone of the first holding unit and the second holding unit, and neitherthe first vibrating member nor the second vibrating member is held bythe other one of the first holding unit and the second holding unit. 6.The drive system as claimed in claim 2, wherein at least one of thefirst vibrating member and the second vibrating member is a drivingdevice to drive itself as a drive source.
 7. An image forming apparatuscomprising: the drive system as claimed in claim
 1. 8. A drive systemcomprising: at least one vibrating member to generate vibration when itis driven; and a holding system to hold the at least one vibratingmember, wherein the holding system at least includes a first holdingunit and a second holding unit, the first holding unit and the secondholding unit superimposed on and partially connected to each other, andthe first holding unit and the second holding unit are made of differentmaterials.
 9. A drive system comprising: at least one vibrating memberto generate vibration when it is driven; and a holding system to holdthe at least one vibrating member, wherein the holding system at leastincludes a first holding unit and a second holding unit, the firstholding unit and the second holding unit superimposed on and partiallyconnected to each other, and a connecting position, at which the firstholding unit and the second holding unit connect to each other, ischangeable in accordance with a magnitude of vibration transmitted tothe first holding unit and the second holding unit.
 10. A drive systemcomprising: at least one vibrating member to generate vibration when itis driven; and a holding system to hold the at least one vibratingmember, wherein the holding system at least includes a first holdingunit and a second holding unit, the first holding unit and the secondholding unit superimposed on and partially connected to each other, andthe second holding unit is shaped not to contact either the firstvibrating member or the second vibrating member contacting the firstholding unit.
 11. The drive system as claimed in claim 10, wherein athickness of the second holding unit in a direction, in which the firstholding unit and the second holding unit are superimposed, is variablein accordance with a magnitude of vibration transmitted to the secondholding unit.
 12. A drive system comprising: at least one vibratingmember to generate vibration when it is driven; and a holding system tohold the at least one vibrating member, wherein the holding system atleast includes a first holding unit and a second holding unit, the firstholding unit and the second holding unit superimposed on and partiallyconnected to each other, and one of the first holding unit and thesecond holding unit has a greater rigidity than the other one of thefirst holding unit and the second holding unit.
 13. The drive system asclaimed in claim 12, wherein the one of the first holding unit and thesecond holding unit is thicker than the other one of the first holdingunit and the second holding unit.
 14. A drive system comprising: atleast one vibrating member to generate vibration when it is driven; anda holding system to hold the at least one vibrating member, wherein theholding system at least includes a first holding unit and a secondholding unit, the first holding unit and the second holding unitsuperimposed on and partially connected to each other, and one of thefirst holding unit and the second holding unit includes a reinforcedportion having enhanced rigidity, the reinforced portion excluding aportion in which the first holding unit and the second holding unit aresuperimposed on and partially connected to each other.